This application relates to an apparatus for restarting an engine and more particularly to methods of transferring angular momentum between the engine and apparatus. The present invention has as an object of reducing fuel consumption for automotive vehicles. It can be demonstrated that if an automotive engine is automatically turned off during periods when the vehicle is stationary, in an idling condition or during periods of deacceleration, fuel consumption will be reduced. The invention, as described in detail below, is widely applicable to automotive vehicle operation in dense city traffic during which operation of the vehicle is continually maintained at idle. Once an engine has been turned off it can be restarted in a conventional manner using the starter motor. A deficiency in using the starter motor is excessive noise, accelerated wear and a reduction of the reliability of the starter motor-engine combination. The present invention utilizes a momentum wheel or flywheel that is directly connected to the engine crankshaft which results in a superior method and apparatus for automatically restarting a stalled or shutdown engine. The utilization of a direct connection to the engine's crankshaft eliminates the need for external belts, gears, and chains to power the momentum wheel. However, such an indirect connection is within the purview of the present invention. Accordingly, the present invention comprises:
An idle restart clutch adapted to mechanically engage the crankshaft of an engine for use in restarting the same comprising:
spool body means adapted to engage the crankshaft for rotating therewith;
momentum wheel means mounted relative to the crankshaft for storing rotational energy;
driving means mounted between said spool body means and the momentum wheel means for transferring the rotational energy from said spool body means to the momentum wheel means during intervals as determined by the rotational speed differential therebetween;
torque limiting clutch means mounted to and rotatable with the momentum wheel means wherein the clutch means includes a plurality of friction surfaces engaging corresponding surfaces of the momentum wheel means thereby permitting controlled slippage motion therebetween including an electromagnetic coil attached to and rotatable with said spool body means and overwrapping clutch means attached to and rotatable with the clutch means wherein the overwrapping band is drawn into contact with the spool body means in response to control signals to enable the energy of the momentum wheel to be transferred to the spool body and thereafter to the crankshaft of the engine to enable rotation of the same. In one embodiment of the invention the driving means comprise a one-way bearing, shoe holder and spring loaded shoes which drive the flywheel. In an alternate embodiment of the invention the overwrapping clutch means is used as the drive means to selectively drive and disengage the flywheel.